// Copyright 2006-2007 javascript-array.com

            var timeout	= 500;
            var closetimer	= 0;
            var ddmenuitem	= 0;

            // open hidden layer
            function mopen(id)
            {	
	            // cancel close timer
	            mcancelclosetime();

	            // close old layer
	            if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';

	            // get new layer and show it
	            ddmenuitem = document.getElementById(id);
	            ddmenuitem.style.visibility = 'visible';

            }
            // close showed layer
            function mclose()
            {
	            if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
            }

            // go close timer
            function mclosetime()
            {
	            closetimer = window.setTimeout(mclose, timeout);
            }

            // cancel close timer
            function mcancelclosetime()
            {
	            if(closetimer)
	            {
		            window.clearTimeout(closetimer);
		            closetimer = null;
	            }
            }

            // close layer when click-out
            document.onclick = mclose;